Kingdom Hearts 3 will be the culmination of every Kingdom Hearts game that has come before it, and while that is leading to a very intentional story, its developers are open to expanding the game with DLC after launch.
Speaking at E3 2018, Kingdom Hearts franchise director Tetsuya Nomura told IGN he wants to have post-launch content in Kingdom Hearts 3. But, don’t expect any concrete announcements of what that DLC could be just yet.
“In this day and age, most major titles do have some kind of content releases after their release,” Nomura told IGN via translation. “So since I considered Kingdom Hearts 3 to be one of those major titles, I do want to have something to add to your enjoyment of Kingdom Hearts 3, so maybe you could continue to play a little longer than release, but we haven’t really thought of anything in detail yet.”
Source: IGN.com Kingdom Hearts 3 Director on Potential for DLC